The proposed investigations have the objective of exploring the etiology of drug abuse with special regard to the high vulnerabilities shown by minority populations. Three Major objectives are addressed (1) Identifying the cultural factors which affect the vulnerabilities of minority juvenile populations to substance abuse, (2) Developing advanced measurement capabilities which allow identification of high risk sub-populations among minority groups, and (3) Providing information specifically relevant to substance abuse prevention and treatment programs for minority youth. This research will examine the relationship between acculturation and substance abuse in the context of Puerto Rican samples of addict and non-addict populations. An in-depth analysis of the processes of social learning and socialization through which Puerto Ricans adapt to the American cultural environment will be performed. Analyses will focus on changes in self-image, social nexus, and other strategically selected areas of perceptions and value orientations involved in the transition from a traditional to a post-modern frame of reference or behavioral organization. This research will identify those critical parameters of psychocultural dispositions (e.g. self-image, the perceptions of substances, perceptions of treatments, fears, and anxieties) which can offer sensitive indicators about vulnerabilities, and offer a solid foundation for identifying high-risk subpopulations characterized by low resistance and high vulnerabilities among Puerto Ricans living in the Continental United States. This research will produce new psycho-cultural information relevant to the prevention and treatment of substance abuse in Hispanic populations as well as make the extensive psycho- cultural information already accumulated on Hispanics relevant to prevention and treatment. This research will relate the critical parameters of acculturation to the parameters of cognitive organization which are related to substance abuse.